package com.xie.leetcode.array;

//请你判断一个 9x9 的数独是否有效。只需要 根据以下规则 ，验证已经填入的数字是否有效即可。
//
//        数字 1-9 在每一行只能出现一次。
//        数字 1-9 在每一列只能出现一次。
//        数字 1-9 在每一个以粗实线分隔的 3x3 宫内只能出现一次。（请参考示例图）
//        数独部分空格内已填入了数字，空白格用 '.' 表示。
//
//        注意：
//
//        一个有效的数独（部分已被填充）不一定是可解的。
//        只需要根据以上规则，验证已经填入的数字是否有效即可。
//         
//
//        示例 1：
//
//
//        输入：board =
//        [["5","3",".",".","7",".",".",".","."]
//        ,["6",".",".","1","9","5",".",".","."]
//        ,[".","9","8",".",".",".",".","6","."]
//        ,["8",".",".",".","6",".",".",".","3"]
//        ,["4",".",".","8",".","3",".",".","1"]
//        ,["7",".",".",".","2",".",".",".","6"]
//        ,[".","6",".",".",".",".","2","8","."]
//        ,[".",".",".","4","1","9",".",".","5"]
//        ,[".",".",".",".","8",".",".","7","9"]]
//        输出：true
//        示例 2：
//
//        输入：board =
//        [["8","3",".",".","7",".",".",".","."]
//        ,["6",".",".","1","9","5",".",".","."]
//        ,[".","9","8",".",".",".",".","6","."]
//        ,["8",".",".",".","6",".",".",".","3"]
//        ,["4",".",".","8",".","3",".",".","1"]
//        ,["7",".",".",".","2",".",".",".","6"]
//        ,[".","6",".",".",".",".","2","8","."]
//        ,[".",".",".","4","1","9",".",".","5"]
//        ,[".",".",".",".","8",".",".","7","9"]]
//        输出：false
//        解释：除了第一行的第一个数字从 5 改为 8 以外，空格内其他数字均与 示例1 相同。 但由于位于左上角的 3x3 宫内有两个 8 存在, 因此这个数独是无效的。
//         
//
//        提示：
//
//        board.length == 9
//        board[i].length == 9
//        board[i][j] 是一位数字或者 '.'
//        相关标签
//        数组
//        哈希表
//        矩阵
//
//        作者：力扣 (LeetCode)
//        链接：https://leetcode-cn.com/leetbook/read/top-interview-questions-easy/x2f9gg/
//        来源：力扣（LeetCode）
//        著作权归作者所有。商业转载请联系作者获得授权，非商业转载请注明出处。

import java.util.HashSet;
import java.util.Set;

/**
 * @author xiezhendong
 * @date 2021/10/21
 */
public class IsValidSudoku {

    public static void main(String[] args) {
        IsValidSudoku isValidSudoku = new IsValidSudoku();

        char[][] board = new char[][]{"53..7....".toCharArray()
                , "6..195...".toCharArray()
                , ".98....6.".toCharArray()
                , "8...6...3".toCharArray()
                , "4..8.3..1".toCharArray()
                , "7...2...6".toCharArray()
                , ".6....28.".toCharArray()
                , "...419..5".toCharArray()
                , "....8..79".toCharArray()};

        System.out.println(isValidSudoku.isValidSudoku(board));

        board = new char[][]{"83..7....".toCharArray()
                , "6..195...".toCharArray()
                , ".98....6.".toCharArray()
                , "8...6...3".toCharArray()
                , "4..8.3..1".toCharArray()
                , "7...2...6".toCharArray()
                , ".6....28.".toCharArray()
                , "...419..5".toCharArray()
                , "....8..79".toCharArray()};
        System.out.println(isValidSudoku.isValidSudoku(board));

        board = new char[][]{"....5..1.".toCharArray()
                , ".4.3.....".toCharArray()
                , ".....3..1".toCharArray()
                , "8......2.".toCharArray()
                , "..2.7....".toCharArray()
                , ".15......".toCharArray()
                , ".....2...".toCharArray()
                , ".2.9.....".toCharArray()
                , "..4......".toCharArray()};
        System.out.println(isValidSudoku.isValidSudoku(board));

    }

    public boolean isValidSudoku(char[][] board) {
        int length = board.length;

        // 行
        for (int i = 0; i < length; i++) {
            Set<Integer> set = new HashSet<>();
            for (int j = 0; j < length; j++) {
                if (board[i][j] == '.') {
                    continue;
                }
                int num = board[i][j] - '0';
                if (!set.add(num)) {
                    return false;
                }
            }
        }

        // 列
        for (int j = 0; j < length; j++) {
            Set<Integer> set = new HashSet<>();
            for (int i = 0; i < length; i++) {
                if (board[i][j] == '.') {
                    continue;
                }
                int num = board[i][j] - '0';
                if (!set.add(num)) {
                    return false;
                }
            }
        }

        // 3*3
        for (int i = 0; i < length; i += 3) {
            for (int j = 0; j < length; j += 3) {

                Set<Integer> set = new HashSet<>();
                for (int x = 0; x < 3; x++) {
                    for (int y = 0; y < 3; y++) {
                        if (board[i + x][j + y] == '.') {
                            continue;
                        }
                        int num = board[i + x][j + y] - '0';
                        if (!set.add(num)) {
                            return false;
                        }
                    }
                }
            }
        }

        return true;
    }
}
